Sawmill operations generate an important percentage of what is usually considered waste or low-grade wooden materials. These wooden materials are often difficult to reuse or recycle, as opposed to waste materials in other industries such as steel, aluminum, plastic, etc. Traditionally, waste and low-grade wooden materials do not have significant value as they are not readily useful due to their lack of size or quality. They are sometimes transformed into wood chips for pulp and paper production, or simply burned or otherwise discarded.
Waste and low-grade wooden materials are resulting from sawmill operations for various reasons. A sawmill typically produces thousands of feet of lumber each day. To achieve this, a large number of logs are processed. Each log is different in size, shape and quality, and as a result, the lumber pieces that can be obtained depend on various factors.
In a sawmill, each log is generally scanned and subjected to a first breakdown in accordance with a log breakdown pattern. The pattern is calculated to obtain an optimum value out of the log. Lumber is produced in accordance with requirements of the clients of the sawmill. The first goal is usually to make a maximum number of large one-piece sections because of their high value. However, since clients order or want lumber with specific lengths, some pieces need to be trimmed. For instance, if a lumber piece is 9.5 feet (285 cm) in length but clients require lumber pieces of 8 feet (240 cm) or 10 feet (300 cm), it must be trimmed to the next smallest length, in this case, 8 feet (240 cm). This results in the waste of 18 inches (50 cm) of the original lumber piece.
Another reason for having waste or low-grade materials is that logs supplied to today""s sawmills have an average diameter which is significantly smaller than those of the past centuries. As a result, lumber with a small cross section is now produced in abundance and market prices are low due to a lack of demand to match the offer.
Some of the wood slabs removed from the outer portion of the log during the first breakdown can be resawed in a second breakdown to recover useful sections, if any. However, the second breakdown generally produces small or low-grade lumber pieces, thus products whose initial value is not significant. Lumber pieces coming from the second breakdown typically have wane somewhere along one or both longitudinal sides. A side with wane is also referred to as a xe2x80x9cwany edgexe2x80x9d. A wany edge is found on lumber that was adjacent to the original cylindrical surface of the log. Unless very small, a wany edge reduces significantly the value of a lumber piece, which is then likely to fall into the low grade category. One way of increasing the value of low-grade lumber is to saw away the wane or wanes, thereby reducing the width of the lumber piece. This process is known as xe2x80x9cedgingxe2x80x9d. Similarly, various other defects in lumber pieces could be removed by trimming them out, and making lumber pieces of smaller lengths. One of the drawbacks of the edging or trimming process is that the size or length of the processed lumber pieces is likely to be smaller than what is ordered or desired by clients.
The present invention relates to a wood board, a process for making the wood board and an apparatus for making the same. This wood board is composed of a plurality of wood pieces, especially short wood pieces, thereby allowing these to be used in a more efficient way. The present invention also provides wood boards with a high degree of structural integrity and dimensional stability. The present invention also allows making wood boards in a new and improved manner. Almost any size and length of wood boards can be made in accordance with what clients need.
In brief, the process comprises the step of joining the wood pieces side by side to form a panel having longitudinal joints defined between two adjacent wood pieces. This panel is then cut in a longitudinal direction, with reference to the wood pieces, into panel sections having similar width. The panel sections are then joined end to end to form the wood board. The result of this process is a wood board having at least two sections, each made of at least two wood pieces of similar length and joined side by side. The sections are jointed end to end with an adjacent one. In this process, the panel is cut so that a majority of longitudinal joints between two adjacent sections are being disposed in an offset manner This process can also be carried out in a continuous manner in an apparatus designed for that purpose.
Other objects, features and advantages of the present invention will be more readily apparent from the following detailed description of preferred embodiments thereof, which proceeds with reference to the accompanying figures which are briefly described hereinafter.